it works in pvp, just highly reduced (instead of 1/4th total life, 1/10 melee, 1/20th ranged **before dr)

tidus, your thinking of critical strike

Critical strike and Deadly strike do not stack, although they have the same affect
(double physical damage)

critical comes from skill, deadly from gear
claw mastery, and all barbarian masteries regardless of the % they say give 100% chance for critical/deadly
hence asns/barbs don't use headstrike/guillaumes/goreriders/highlords/etc

yes you can have deadly strike and crushing blow in the same strike, but they are calculated seperately (crushing blow is physical but you don't leech from it)

open wounds does damage over time based on character level, the formula is

(Attacker level * 9 + 40)/256 pts of damage per frame over 4 seconds